1. Field of Invention
Aspects of the present invention relate to methods and systems for food preparation. More particularly, aspects of the current invention related to methods and systems for pressurized cooking.
2. Background
Food preparation generally involves raising the internal temperature of the food to a specified level. There are a variety of conventional methods for food preparation, such as on top of a flame (e.g., grilling, pan frying, boiling) and in an oven (e.g., baking, broiling). In all methods, the same concept of raising the temperature of the product is the ultimate goal. The manner in which that goal is accomplished affects the taste and the time involved in the cooking process. In a conventional oven, the heat migrates (by conduction) from the outside of the food toward the middle. There may also be dry, hot air on the outside of the food evaporating moisture on the surface of the food product. As a result, the surface of the food product dries out, becoming crispy and brown, while the inside of the food product remains moist.
In recent years, microwave ovens have become commonplace in the household. A microwave oven uses microwaves to heat food. In the case of microwave ovens, the commonly used radio wave (micro wave) frequency is roughly 2,500 megahertz (2.5 gigahertz). Radio waves in this frequency range can be absorbed by water, fats and sugars, and when are absorbed, the radio waves are converted directly into atomic motion, and thus into heat. Microwaves in this frequency range are also not absorbed by most plastics, glasses or ceramics. In microwave cooking, the radio waves penetrate the food product and excite water and fat molecules throughout the food product more evenly than in a conventional over. No heat conduction toward the interior occurs. However, there are drawbacks to microwave cooking, in that the radio waves penetrate unevenly in thick pieces of food and, as such, do not always reach the middle of the food product, and “hot spots” can be caused by wave interference inside the food product.
A method of cooking on a stove top involves the use of a pressure cooker, which is a pot for food preparation that is designed to maintain a pressure above atmospheric pressure. Water in an open pot boils at 100° C. at a standard atmosphere. As the water evaporates and becomes steam, the water remains at the same temperature. The only way to make the steam hotter (and/or to boil the water at a higher temperature) is to increase the pressure, which can be accomplished by a pressure cooker. The heat from the stovetop transfers through the metal pot to the contents (which generally include water and the items being cooked.) Since the pressure cooker is sealed, as the water inside the container expands to steam, the closed environment of the container causes the pressure inside the container to rise. The higher pressure, in turn, results in a higher temperature inside the vessel. For example, at higher pressures, the temperature at which water boils is higher than 100° C. The increased pressure inside the pot delays the water and/or other liquids inside the pot from boiling until the liquid reaches a much higher temperature. As a result, the cooking process is sped up considerably.
However, currently, cooking using an oven is performed at atmospheric pressure and generally takes a long time. As such, there is a need in the art for an improved oven for food preparation products that involves pressurized cooking in an oven.